Now to Josh Powell sister Alina who has been outspoken about who's to blame for her brother's death -- his. Two sons pointing the finger at everyone but her brother. She's speaking out now on an ABC news exclusive and let's go back -- -- I didn't drove in Washington -- happy. Good morning Robin for the first time and Josh -- sister Alina tell GMA why she believes her brother. Killed himself and killed those two kids. I wake up and I feel like. I didn't really happen but it -- against the wall so much. They weren't always. Welcome you. Josh Powell's sister Elaine speaking exclusively to GMA we're calling voicemail she got from her brother just twenty minutes before he blew up his house. Killing himself and his two young sons Charlie in Braden. But not. They don't look don't -- mobile I'm sorry to everyone -- heard. What -- Moments later she called 911. It. Into Stockton street -- looking at this the shell of the house. It was gotten me knows it is just empty hollow and -- Why do you think your brother did the next -- he killed himself and his two young sons. And he -- suit just felt that. That there was only one way left for him to protect his sons from the pain. From. -- very emotional and physical pain that they've been experiencing. But he didn't protect them. I appreciate -- differently. Considering. What we now know Josh was capable. Do you think that he had a role in Susan's disappearance. Have never received any indication from him -- the wounds that he hadn't considered that. And that's me and I look toward the heart. -- locked. I studied every every -- he said every action he -- But does an innocent man students. I can't put myself in his mind. But -- think. He constantly intense. More heartbroken. And I realize that any industrialized. -- also told us that Josh had recently expressed optimism for the future and that he planned to continue fighting. For his aunt for custody of his children. Which it makes is all the more difficult to truly comprehend. Robbins and we thank you.

This transcript has been automatically generated and may not be 100% accurate.

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